Brain Regions and Functions | Ask A Biologist
The effect of color on flavor or odor identification, basic taste odors, the area in the brain stimulated was the piriform/amygdaloid region, the right orbitofrontal. taste, smell, development, genetics, clinical disorders. CONTENTS .. tion is transmitted to areas of the brain involved in control of reproductive behavior and . Planet Money; Hidden Brain When taste buds were discovered in the 19th century, tongue cells under a you will hear Jonah and me "cooking" (the sounds were snatched Meanwhile, halfway across the world, a chemist named Kikunae cheese and meat but not one of the four well-known tastes.
So we'll have those cues of visual cues to say it's okay to eat and then we might smell it and then we might put it into our mouth. So let's do a little bit of that.
Now Herman and Giselle here are going to tuck into something quite delicious, we might reveal to our audience what they're going to be eating. It smells really good doesn't it Giselle? I don't smell anything. Lean forward a little bit, can you smell? Smells good to me. Yeah, I think it smells pretty good. Now I'm going to give you a hand here, why don't we give them a hand?
Okay, I've got some on the fork here. Don't poke yourself in the face. Okay Giselle, here, I'll help you pop that into your mouth. How does that taste? Yeah, what do you think it is? Chicken, it's a bit salty, a bit sort of slimy I guess, is this someone's cooking? Herman's having some fun here. I think it's a meat but it could be like a lamb or something a bit more chewy.
Next, here we go. I'm just going to give you this, there you go. What do you think? Mashed potato, these questions are suspicious. Herman, what do you think it is? Absolutely mashed, potatoes, yeah.
We might take the blind folds off. How do you feel about it eating it now though, now that you can see it? Well the same I guess, it's fine, food colouring. But if I'd put that plate down in front of you?
I wouldn't touch it. You wouldn't touch it? Why wouldn't you touch it? The colours and that, I don't associate the colours as being tasteful. Alright, thank you very much for being our guinea pigs. Round of applause for Giselle and Herman.
Thanks very much James and we might move on. Why do some people taste things more strongly than other people? So the factors that comes into play are really the genetics and so our genes differ between people and that can be, that can cause differences in taste between people. Environment can also influence our taste so whether we smoke, what type of diet we have, if we're exercising, and also prior experience can influence how we taste.
Is there a special group when it comes to taste? Yes, there's been a lot of research around a bitter molecule called PROP and it's been regarded as a marker of taste sensitivity. So some people can detect the bitterness while other people can't detect the bitterness so we've got an experiment we've set up here. So we're going to do now, a group of you have a little cup like this, I've got one too, so we're all going to sample what's in this little cup on the count of three.
Helen, horrible reaction, what does it taste like to you? Okay, grab some water if it tastes really horrible you've all got water. Who else had a really strong reaction? Mine was very bitter. Mine was bitter as well. Did anyone just not taste much at all? Yeah, I'm in that category too. I'm with you so what does this tell us about these people? So this is a great example of how taste varies between people and how our genetics, which is the major component or driver in the ability to perceive the bitterness in the solution.
So does that mean the people who, Helen's still in pain up there. You're obviously a very strong taster of things. Have you got a very strong, are you aware of having a strong sense of taste? Does that have a colour? Yes, did it have a colour, good question? It was like an inky dark grey colour, yeah.
- Taste and Smell
- Coping with taste changes
- Sweet, Sour, Salty, Bitter ... and Umami
Now there are people called super tasters? Is Helen potentially a super taster? Potentially she could be a super taster.
And tell her what that is?
Anatomy of the brain and spine
Yeah, so I suppose what we're seeing is we're seeing two groups, so tasters and non-tasters, but then within that taster group we see people who perceive the bitterness of being much more intense or much greater. So super tasters have been associated with a range of different dietary patterns; So the bitter molecule that we've got in the solution PROP, there are similar molecules in, similar shape molecules in things like brussel sprouts and broccoli and so that has been associated with super tasters actually not being as accepting of those green vegetables.
Do you like broccoli and brussel sprouts? I love them because of their bitterness. And what does it mean for the rest of us who didn't taste anything like you and me, does that mean our taste buds are damaged? Does it mean we're hopeless at tasting foods? No, no, so this is, I suppose, looking at one particular bitter receptor and we've got 25 different bitter receptors.
So we're only looking specifically at one particular receptor. So it doesn't necessarily mean that we're deficient in taste. Another thing that super tasters are associated with is the amount of taste tissue that's present within on the tongue. So super tasters have a higher level of taste tissue and that potentially also could enhance their ability to perceive the bitterness. Does that mean more taste buds?
Yes, so that means more taste buds. Sebastian you tried it, didn't you? And you're a master sommelier? Okay, did you taste the bitterness?
Tell people what a sommelier is for those who might not know? So a sommelier essentially is someone who works within restaurants or for a restaurant group and I guess we look after the buying, serving and storage of wine. There are two in Australia, is that right? There are two master sommeliers now in Australia, myself and another gentleman who is also in Sydney, so four exams essentially to become a master sommelier.
And what do you have to do in those exams? The final examination component is a blind tasting exam and for the final exam that's six wines, so three whites and three reds, you have 25 minutes from the moment you touch the first glass to correctly talk about those wines from the visual, the nose, the palate and then give a conclusion on the wines.
So stating exactly where you think the wine is from, the region, the vintage and the grape variety. So it could be anywhere in the world? It could be anywhere in the world and, yeah. So from taste and smell alone and sight, you have to work out? And how did you do in the exam? And do you rely on one particular sense more than others do you think to do this? I've yeah, it's a really hard one to answer. I think I rely on, if we're in a blind tasting situation and I'm trying to guess where a wine is from, probably on red wines I rely more on palate assessment.
But potentially for whites maybe more on the aromatic profile. Is it a skill you've always had? Could anyone train to do it do you think? I think probably the heights that you get to might be limited through genetics and kind of how everyone's built, acidity in wine you can learn how you perceive these things; tannin in wine. Jason, just reaction to all of that?
For most of us who live in a visual world, we're quite happy that we can recognise lots of different kind of visual objects, chairs and tables and people's faces and so on. But we don't really think about flavours and smells as objects per se. And I guess in cases like this people have learned to do that kind of complex object recognition but for flavours and for aromas.
Julee-anne, what your sense of taste like? Well apparently really poor. I thought it was water, and I'm the person who sniffs around our house and goes there's something, there's something and it will like a milligram of fruit in my son's school bag and I'll find it. The children have worse names but I think that, I like this idea because, because my sense of smell at the moment is quite impaired because I'm unwell, my sense of taste seems to be impaired and I would imagine that there's a link.
Melinda, you lost your sense of smell nine years ago, what's that like? I guess, I guess on a day-to-day basis life doesn't change, you can still do all of the things that you do. But you become, you become more aware of things in your house like a smoke detector that becomes incredibly important for your safety. Not being able to smell food when it's bad. Do really bad, bad, bad smells ever register with you? You know, I work in a school and I've helped kids who have been ill and you'll be helping them with a bag and you're having a little dry retch and it will be alright and trying to look away.
But I can't smell it but I know what's happening. How did you lose your sense of smell? I have and still have allergic nasal polyps that grew and that grow in my sinus spaces and they've, they've damaged my sense of smell and I've had them surgically removed twice and the surgery that's performed to remove nasal polyps can also damage your sense of smell. Will you get it back do you think? My smell comes back with oral steroids.
But you obviously can't take those on a, they're a very, very short term thing to take because there are lots of other side effects. But what it does, what they do is really reduce down all of the inflammation and I get my sense of smell back for the short period of time and it's lovely. I can but I think my taste is diminished and I'm one of the failures in that last test. I had a little bit of bitterness at the back of my tongue.
Do you miss that? Yes, I do, and I think the two significant ones for me, my dad's after shave. It was an after shave that my mum bought him when they were courting and he wore it all his life and that's his smell and of course I'll, you know, I'll never smell that again. And the other thing that I was very aware of missing out on was when my brother and his wife had their kids, so I've never, you know, my two nephews and my niece, I've never smelt that baby smell and so I was, you know, very conscious of missing out on that kind of thing.
James, not having a sense of smell is called anosmia. How many people in Australia does it affect? It's not certain, it's thought about 1 percent of people report they can't smell, but as you saw tonight, Herman was trying to smell a chicken and couldn't really smell the chicken so a lot of us have temporary loss of smell, but about 1 percent have a significant on-going loss of smell.
Can you get it back or once it's gone, is it gone? Well you can get it back, the nerve cells can regenerate and it's the only part of the nervous system that regenerates every single day of our lives in normal healthy people. And so I'm working on a therapy to cure spinal cord injury and spinal cord paralyses by using cells from the nose to transplant them in the spinal cord because it's the only part of the nervous system that regenerates, very special cells there that allow those nerve cells to make connections with the brain.
Not perfect but still the first time they've got connections and so understanding how the brain can regenerate in one part can allow us to get therapies in other areas.
Toby, you're an air traffic controller, tell us how many things do you have to do at once? It can range from one thing to I suppose things. Whether they're concurrently or within close succession I suppose would be a debate for the experts.
Probably the more simple situations not so many, you may be doing only two, thinking and talking or even three, you know, writing, thinking and talking and at the start of training that's something that sounds quite simple but it's quite difficult actually to think about speaking and writing. The more complex situations where you're solving a confliction between maybe five aircraft you're thinking about a plan for each one of those aircraft, you're administering the plan and providing instructions in the right order to make sure everything works and then you're constantly assessing what you're doing to make sure everything's coming off as well.
Yeah, I mean particularly in the tower environment, we have air space out to about five nautical miles when you're talking about a normal jet aircraft landing it's doing two to three miles per minute. We're talking about a minute from when they call us on frequency to when the situation is resolved.
So we have a lot of decisions to make in a very short space of time. Which of your senses would you use the most? I think in a control tower probably visual and audio obviously because all our instructions are given verbally and we receive read backs verbally through the radio as well. So we probably supplement our visual observation with what we're hearing and checking those match up.
How stressful is it? Commonly asked question, would you believe? So in an air traffic control environment a situation may require you raise your work rate to suit the workload, it can become quite acutely stressful but once you've dealt with the problem the stress vanishes fairly quickly.
Well it's so intense, you're only allowed to do it for what, two hours at a time? Before you have a break? Yeah, we work for two hours before we have a break. What do you do to recharge? I'll just veg out on the couch and tune out from the outside world. Could anyone do what Toby does? Well I think with some training, maybe, I mean there may be certain predispositions that allow some people to do a better job of that than others. But there's really sort of hard limits to how much multi-tasking any of us can do.
Can we test our ability to multi-task or to do this, prioritise? We can and there are all kinds of sophisticated scenarios. You know, in a laboratory environment we could give people different sources of information to monitor and test their abilities and look at mistakes they make and so on. You've got a test here?
Taste Science - To the Brain
We have a test, yeah, and this is really, I guess it's really a test of attention in some ways but it does require you to look at a display and to track multiple objects and so here we go, you're going to track two squares, they're the two you need to keep track of and they'll start moving. Keep track of them. So it starts to get difficult as the squares start to intermingle with one another but hopefully you've still got two of those particular squares that you're attending to.
Okay, who got it right? How many, hands up, up high. How many people got it right? Yeah, pretty good, pretty much everybody. Pretty much I'd say 90 percent of the people here were able to do that. But of course now we can actually make it more difficult, the second one that you'll see, now keep track of the all four of these. So that's the cue that you'll get, they're the ones. You need to try to keep track of all four of those squares now as they move around and again as they start to intermingle with one another it gets a little bit more difficult to keep track of them.
How are you going everyone? Oh, I'm not supposed to interrupt your concentration. Okay, hands up how many people got it? How many got all four? Okay, how many got just three, just two? Okay, there's some honest people. So can we train ourselves to get better at doing something like that? Yeah, if you train on tasks like this you can actually get a little bit better. For most of us there is a really hard limit and it turns out to be about four items. If you really practice intensively perhaps you can get up to five or six but not much beyond that.
Toby, do you have a hard limit with your job? Yeah, you definitely do. I can probably identify more the sensation of approaching that hard limit than the actual number of things I'm processing concurrently but you're definitely trained, you know, to recognise when you're approaching that limit and to start implementing strategies to make sure you don't exceed it.
Yeah, because again the stakes are high if you get something wrong? Do you multi-task in the rest of your life? Very much so, yeah. So I have a question, do you do that by rapidly switching from one to another, or do you literally process all three at the same time?
It would be very difficult to say but I think you're probably right. You actually listen for key words in each conversation. The thing is an air traffic controller, you learn key words in each conversation which really are trigger words and your attention is then dedicated to that one which requires the priorities. The work "take off" or "cleared to land", we only use in conjunction with a clearance to take off or to land.
We would never say "expect to take off" because for those exact reasons, it can introduce expectation by a switch could be dangerous in the wrong circumstances. Jason, why is understanding how attention works important?
How can it help us in other ways? We rely on attention to filter information, to guide our safe behaviour and so, you know, if we're monitoring a normal world where we have audio information, visual information, touch information and so on, there's got to be some way of prioritising those things. So doing something like driving a car, you need in be able to pay attention to the right thing at the right moment in time to avoid accidents.
So there are really pragmatic reasons for this. It's one of the reasons that it's illegal to drive and text or to drive and use a mobile phone because it doesn't just take your eyes off the road, it actually use us up some of your attention and if that part of your attention is used up, you have a less of that left over to help you drive a safely. I'm interested in the applications of all this work that you're all doing as scientists around the senses and Anina, I know you study people with Synaesthesia, why?
I'm interested in the way that the brain puts the information together from all the senses and integrates it with what we already know. And Synaesthesia is a phenomena in which we have this unique window into that because it's an internally generated experience. It's associated with, for example, a sound or seeing a letter or hearing a word that most of us don't have, but it might be the same sort of thing where there's a pre existing association, a long term knowledge about something, and it influences the way that you perceive that information coming in from the world.
And what do you understand about why Synaesthesia happens? Why is always a tricky one. So people who might hear programs like tonight and suddenly go wow, I do that and have never met anyone else who does it. There's some sense in which it might be helpful for creativity. So one of our studies we found that a much greater proportion of Synaesthetists are involved in creative occupations than the general population. But again, it's kind of hard to say the why. Jason, we hear a lot about brain plasticity now and I'm just wondering about the repair of certain senses though.
I mean is there potential for the brain to actually act to repair damaged senses? So we know that after damage to the brain caused by stroke, for example, there can be a spontaneous repair. But also other sense modalities can start to take over some of those functions.
So if one loses a sense of sight, then as we've heard tonight you can start to rely on other sense modalities to help you pick up cues in the environment and help guide you around. Julee-anne, what have you learnt about the capacity of your senses? I think what's interesting is the main thing that's being trained when you're learning echo location isn't necessarily the sense of sound or the sense of hearing, it's the perceptual system. So what we're doing is we're turning on the perceptual system in your brain and we're allowing you to take the sound that you hear and create within your, within your mind an image of what it is that the sound is reflective of.
Toby, what have you learnt about your senses do you think in your job?
I think very similar to flight crew you need to be very careful not to blindly trust only one input because there can be frequent occasions where things are actually at odds with one another. So a healthy mistrust is always beneficial. Sebastian, what about you, what have you learned about your own sensory capacity? I think I've learnt to trust them as much as anything and I think probably with wine tasting it's something that you, over time you just become more confident in your own senses and your own ability to taste and perceive things.
Okay, Catherine and Jennifer, what you have learnt? It's just another tool, I use it as another tool and can you turn one sense off, visual, for instance, playing music, if you can turn off the visual looking at music and rely on the Synaesthesia in your ear to play the music instead of visual.
So rely on the colours? Is that a rich life? Yeah, particularly because we kind of deal with colour and that kind of thing every day it just adds to it. It's like a super colour. Fantastic note to end on. Thank you all so much, it's been really interesting talking to you all and that is all we have time for here but let's keep talking on Twitter and on Facebook.
You can also go to our website by the way for more ways to test your own senses. Thanks everybody, it was great. And when the Greek philosopher Democritus took up the question several thousand years ago, he added bitter. So that makes four. Democritus said not because he did any experiments; being a philosopher, he thought for a living that when you chew on your food and it crumbles into little bits, those bits eventually break into four basic shapes. When something tastes sweet, he said, it is because the bits are "round and large in their atoms.
Everything we taste is some combination of those four ingredients. And that made sense to Plato, and made sense to Aristotle, and pretty much ever since even modern scientists have said that's the number: When taste buds were discovered in the 19th century, tongue cells under a microscope looked like little keyholes into which bits of food might fit, and the idea persisted that there were four different keyhole shapes.
An illustration of taste buds from Gray's Anatomy of the Human Body. And then, along came Auguste Escoffier. What the Chef Tasted Escoffier was a chef. Not just a chef, in Paris in the late s he was the chef.
He had opened the most glamorous, most expensive, most revolutionary restaurant in the city. He had written a cookbook, The Guide Culinaire. Escoffier invented veal stock. And should you choose to listen to our broadcast on Morning Edition, you will hear Jonah and me "cooking" the sounds were snatched from sound effects records, but I think you will drool anyway what was then considered a spectacularly new sauce that seemed to deepen and enrich the flavor of everything it touched.
This was the best food you ever tasted in your life. People may smack their lips, drool, savor and pay enormous amounts of money to M. Escoffier, but what they were tasting wasn't really there. It was all in their heads. What the Japanese Soup Lover Tasted Meanwhile, halfway across the world, a chemist named Kikunae Ikeda was at the very same time enjoying a bowl of dashi, a classic Japanese soup made from seaweed. He too sensed that he was tasting something beyond category.
Dashi has been used by Japanese cooks much the way Escoffier used stock, as a base for all kinds of foods. And it was, thought Ikeda, simply delicious. Soy sauce contains the taste glutamate, but the Japanese call the flavor "umami," which means yummy.